A subscriber host may be reachable across a provider network via two or more pseudowires or other connections or paths. A pseudowire may be used to transport Ethernet frames, or other layer two data, via a layer three network, such as an IP network. Pseudowires have been used, for example, to transport Ethernet frame across a provider network, e.g., between provider edge routers, to provide services such as virtual leased line (VLL) and virtual private network (VPN) services. In some contexts, a subscriber host, or a group of hosts, may be served by a DSLAM or other access node that has access to a core provider network via two or more separate provider edge switches/routers, each of which may be reached by an endpoint at a far end of the core provider network by a different pseudowire or other connection. In some embodiments, the pseudowires may be associated with a particular service, subscriber, or other context with which the subscriber host is associated.
In such a configuration, it may be desirable to ensure that traffic associated with the subscriber host and/or the service or other context with which it is associated, pass through a designated one of a plurality of switches/routers (or other chassis) via which the subscriber host has connectivity to the core provider network, for example to facilitate accounting and other recordkeeping and/or to enforce policies such as service level agreements, quality of service commitments, etc. In addition, it is desirable that traffic not be lost or delayed unduly in the event of a link failure and/or switchover to a standby state, as could occur if a switch/router simply stopped forwarding, accepting, and/or receiving traffic associated with a service or other context with respect to which it has entered a standby state and/or with respect to which it has suffered a link or other failure.